Body broadly oval or rotund; round in lateral view; body dark purple, bright red when crushed, covered by thick filamentous ovisac secretion, individuals usually distinct in heavy infestations; body not visible through secretion. Occurring on pads of host.
Dactylopius opuntiae is most similar to D. ceylonicus (Green) by having 1 size of enlarged seta scattered over dorsum. Dactylopius opuntiae differs by having longer, more slender setae, length/ width 1.3 to 1.6 (length/ width 0.7 to 1.2 on D. ceylonicus).
U.S. quarantine notes
This species was intercepted 160 times at U. S. ports-of-entry between 1995 and 2012, with specimens originating from Mexico. We also have examined specimens taken in quarantine from Mexico (Opuntia) including 13 different interceptions from 1925 to 1992. ScaleNet includes hosts in the genera Cereus, Mammillaria, and Opuntia in the Cactaceae from all zoogeographic regions. The species seems to prefer flat padded species of Opuntia. No species of Dactylopius other than D. coccus Costa, D. confusus (Cockerell), D. opuntiae, and D. tomentosus (Lamark) have been taken at U. S. ports-of-entry.